High-precision RTK GPS technology was used to survey the movements of typical coastal dunes, including a coastal crescent dune and a coastal transverse ridge, in the Feicuidao region of the Changli Gold Coast in Hebei...High-precision RTK GPS technology was used to survey the movements of typical coastal dunes, including a coastal crescent dune and a coastal transverse ridge, in the Feicuidao region of the Changli Gold Coast in Hebei Province in 2006-2008. Our data provide information on the direction, type, and velocity of coastal dune movements, and indicate that the coastal dunes in this re- gion are characterized as slow and landward advancing, with to-and-fro fluctuations. The bottom of the studied coastal transverse ridge was stable during the observation period but the position of its crest advanced eastward (seaward) during summer and au- tumn, and moved landward (westward) in winter and spring. Thus, its crest moved generally landward (westward) but fluctuated to-and-fro eastward and westward. In contrast, the entire coastal crescent dune advanced landward (westward) in a to-and-fro manner, and the velocity of its movement was faster than that of the transverse ridge dune. These results are mainly related to the wind conditions in the research area, the height and volume of the two types of coastal dunes.展开更多
The impacts of desertification on the vegetation composition, structure, and species diversity of alpine Kobresia steppe meadow were evaluated in an area of severe desertification in Anduo County, Tibet Autonomous Reg...The impacts of desertification on the vegetation composition, structure, and species diversity of alpine Kobresia steppe meadow were evaluated in an area of severe desertification in Anduo County, Tibet Autonomous Region, northern China. We investigated and analyzed the floristic features of communities at four different stages of desertification (slight desertification [SLD], moderate desertification [MD], severe desertification [SD], and very severe desertification [VSD]). The composition and structure of the alpine Kobresia steppe meadow at the SLD site differed significantly from that at the MD, SD, and VSD sites. Species that were more drought resistant and inedible by livestock were the dominant species at the SD site. No plants were found in the shifting dunes of the VSD site. Species diversity also decreased with increasing desertification. The SLD site had the largest mean number of species and individuals and the largest richness index; the MD grassland had the largest Shannon-Wiener index and evenness index, but the smallest Simpson’s index. The vegetation cover declined from 91.8% to 34.8% as desertification increased from SLD to SD, and reached 0% in VSD areas with shifting dunes.展开更多
Recent progress of coastal aeolian research in China is reviewed and summarized. Topics considered include coastal dune type, distribution, formation and evolution, characteristics of modem and ancient sediments, and ...Recent progress of coastal aeolian research in China is reviewed and summarized. Topics considered include coastal dune type, distribution, formation and evolution, characteristics of modem and ancient sediments, and observations of sand transport of coastal aeolian dunes in China. Following international trends in aeolian research, research directions for the near future in China are suggested which focus on observation and modeling of coastal aeolian transport processes, the relationship between coastal aeolian processes and global change, a surfzone-beach-dune interaction model, and the problem of coastal aeolian damages in China.展开更多
The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes t...The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes the distribution and forms, sedi- mentary characteristics, formation mechanism, developing age, reddening process and the paleo-environment, suggesting that the Old Red Sand is mainly aeolian sediment of Late Pleistocene Age. The reddening process is mainly the result of decomposition and oxidation of iron-containing minerals caused by hot and humid tropical and sub-tropical climate. In this study, existing prob- lems are discussed and the prospect of further research is presented as well.展开更多
Localized surface plasmon resonance(LSPR)has been widely used in medical detection because of its time effectiveness,noninvasiveness,high sensitivity,and relatively simple fabrication process.Porous anodic alumina(PAA...Localized surface plasmon resonance(LSPR)has been widely used in medical detection because of its time effectiveness,noninvasiveness,high sensitivity,and relatively simple fabrication process.Porous anodic alumina(PAA)can be regarded as a plasma substrate for label-free detection due to its unique two-dimensional structure.In this work,a vivid Au-PAA composite film with the inverted taper structure was developed by multi-step anodic oxidation and pore-widening processes followed by magnetron sputtering with Au nanoparticles(AuNPs).The highly saturated and bright structural color was generated by the synergistic effect of photonic and plasmonic modes.Interestingly,various Au-PAA composite films with structural colors altering from purple to red were obtained via adjusting the height/diameter ratio of PAA.Benefiting from the inverted taper structure,light trap characteristics were effectively enhanced by increasing the incident light and reducing the diffuse light.In addition,a finite difference time domain(FDTD)model was proposed to predict the relationship between the reflectance peak and the height of the composite film,and the simulated data were in good agreement with the experimental results.As a proof of concept,labelfree detections of various reagents(water,ethanol,glycol,glycerol,and glucose),the concentration of glucose(refractive index sensitivity of 376 nm/RIU,RIU:refractive index unit),and thrombin(detection limit of 0.1×10^(-7)mol/L)were realized by the Au-PAA composite film.This vivid Au-PAA composite film provides a very powerful tool for in-situ label-free bio-detection.展开更多
Precise and sensitive bioanalysis has been the major and urgent pursuit in pathologic diagnosis,food safety,environment monitoring,and drug evaluation.Photoelectrochemical(PEC)bioanalysis,as one of the most promising ...Precise and sensitive bioanalysis has been the major and urgent pursuit in pathologic diagnosis,food safety,environment monitoring,and drug evaluation.Photoelectrochemical(PEC)bioanalysis,as one of the most promising detection technologies,has rapidly expanded within the field of analysis.However,most of reported PEC analysis approaches still suffer from weak external anti-interference ability,high background,and the risk of false positive or negative errors due to their inherent single-signal readout.To overcome these shortcomings,new PEC-coupled dual-modal analysis approaches have been developed,where a dual-response signal can be derived through two completely different mechanisms and independent signal transduction pathways.This review introduces the basic principles of PEC biosensing and enumerates and classifies the substrate or probe selections,constructions,and applications of PEC-coupled dual-modal biosensors.Furthermore,the challenges and developmental prospects of PEC-coupled dual-mode sensing technologies are evaluated and discussed.We hope that this review will provide valuable insights into the latest advancements and practical applications of dual-mode PEC bioanalysis,which will be of great interest to those seeking to stay informed in this field.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 40571019 and 40971007)
文摘High-precision RTK GPS technology was used to survey the movements of typical coastal dunes, including a coastal crescent dune and a coastal transverse ridge, in the Feicuidao region of the Changli Gold Coast in Hebei Province in 2006-2008. Our data provide information on the direction, type, and velocity of coastal dune movements, and indicate that the coastal dunes in this re- gion are characterized as slow and landward advancing, with to-and-fro fluctuations. The bottom of the studied coastal transverse ridge was stable during the observation period but the position of its crest advanced eastward (seaward) during summer and au- tumn, and moved landward (westward) in winter and spring. Thus, its crest moved generally landward (westward) but fluctuated to-and-fro eastward and westward. In contrast, the entire coastal crescent dune advanced landward (westward) in a to-and-fro manner, and the velocity of its movement was faster than that of the transverse ridge dune. These results are mainly related to the wind conditions in the research area, the height and volume of the two types of coastal dunes.
基金financially supported by the National Natural Science Foundation of China (Grant No. 40271012)the Science & Technology Committee of the Tibet Autonomous Region (Grant No. 200101046)PHD foundation of Foshan university
文摘The impacts of desertification on the vegetation composition, structure, and species diversity of alpine Kobresia steppe meadow were evaluated in an area of severe desertification in Anduo County, Tibet Autonomous Region, northern China. We investigated and analyzed the floristic features of communities at four different stages of desertification (slight desertification [SLD], moderate desertification [MD], severe desertification [SD], and very severe desertification [VSD]). The composition and structure of the alpine Kobresia steppe meadow at the SLD site differed significantly from that at the MD, SD, and VSD sites. Species that were more drought resistant and inedible by livestock were the dominant species at the SD site. No plants were found in the shifting dunes of the VSD site. Species diversity also decreased with increasing desertification. The SLD site had the largest mean number of species and individuals and the largest richness index; the MD grassland had the largest Shannon-Wiener index and evenness index, but the smallest Simpson’s index. The vegetation cover declined from 91.8% to 34.8% as desertification increased from SLD to SD, and reached 0% in VSD areas with shifting dunes.
基金supported by the National Natural Science Foundation of China (Nos. 40571019, 40971007)
文摘Recent progress of coastal aeolian research in China is reviewed and summarized. Topics considered include coastal dune type, distribution, formation and evolution, characteristics of modem and ancient sediments, and observations of sand transport of coastal aeolian dunes in China. Following international trends in aeolian research, research directions for the near future in China are suggested which focus on observation and modeling of coastal aeolian transport processes, the relationship between coastal aeolian processes and global change, a surfzone-beach-dune interaction model, and the problem of coastal aeolian damages in China.
基金supported by National Natural Science Foundation of China (No. 40971007)
文摘The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes the distribution and forms, sedi- mentary characteristics, formation mechanism, developing age, reddening process and the paleo-environment, suggesting that the Old Red Sand is mainly aeolian sediment of Late Pleistocene Age. The reddening process is mainly the result of decomposition and oxidation of iron-containing minerals caused by hot and humid tropical and sub-tropical climate. In this study, existing prob- lems are discussed and the prospect of further research is presented as well.
基金This work was funded by the National Natural Science Foundation of China(No.51873145)the Excellent Youth Foundation of Jiangsu Scientific Committee(No.BK20170065)+1 种基金the Qing Lan Project,the 5th 333 High-level Talents Training Project of Jiangsu Province(No.BRA2018340)the Six Talent Peaks Project in Jiangsu Province(No.XCL-79).
文摘Localized surface plasmon resonance(LSPR)has been widely used in medical detection because of its time effectiveness,noninvasiveness,high sensitivity,and relatively simple fabrication process.Porous anodic alumina(PAA)can be regarded as a plasma substrate for label-free detection due to its unique two-dimensional structure.In this work,a vivid Au-PAA composite film with the inverted taper structure was developed by multi-step anodic oxidation and pore-widening processes followed by magnetron sputtering with Au nanoparticles(AuNPs).The highly saturated and bright structural color was generated by the synergistic effect of photonic and plasmonic modes.Interestingly,various Au-PAA composite films with structural colors altering from purple to red were obtained via adjusting the height/diameter ratio of PAA.Benefiting from the inverted taper structure,light trap characteristics were effectively enhanced by increasing the incident light and reducing the diffuse light.In addition,a finite difference time domain(FDTD)model was proposed to predict the relationship between the reflectance peak and the height of the composite film,and the simulated data were in good agreement with the experimental results.As a proof of concept,labelfree detections of various reagents(water,ethanol,glycol,glycerol,and glucose),the concentration of glucose(refractive index sensitivity of 376 nm/RIU,RIU:refractive index unit),and thrombin(detection limit of 0.1×10^(-7)mol/L)were realized by the Au-PAA composite film.This vivid Au-PAA composite film provides a very powerful tool for in-situ label-free bio-detection.
基金the National Natural Science Foundation of China(Nos.52303153 and 51873145)the Basic science(Natural science)research project in universities of Jiangsu Province(No.23KJB150035)+2 种基金the Excellent Youth Foundation of Jiangsu Scientific Committee(No.BK20170065)the Qing Lan Project,the 5th 333 High-level Talents Training Project of Jiangsu Province(No.BRA2018340)the Six Talent Peaks Project in Jiangsu Province(No.XCL-79).
文摘Precise and sensitive bioanalysis has been the major and urgent pursuit in pathologic diagnosis,food safety,environment monitoring,and drug evaluation.Photoelectrochemical(PEC)bioanalysis,as one of the most promising detection technologies,has rapidly expanded within the field of analysis.However,most of reported PEC analysis approaches still suffer from weak external anti-interference ability,high background,and the risk of false positive or negative errors due to their inherent single-signal readout.To overcome these shortcomings,new PEC-coupled dual-modal analysis approaches have been developed,where a dual-response signal can be derived through two completely different mechanisms and independent signal transduction pathways.This review introduces the basic principles of PEC biosensing and enumerates and classifies the substrate or probe selections,constructions,and applications of PEC-coupled dual-modal biosensors.Furthermore,the challenges and developmental prospects of PEC-coupled dual-mode sensing technologies are evaluated and discussed.We hope that this review will provide valuable insights into the latest advancements and practical applications of dual-mode PEC bioanalysis,which will be of great interest to those seeking to stay informed in this field.